New research flips the picture for sage-grouse health in NE Wyoming
Northeastern Wyoming is tough country for sage-grouse. The sparse sagebrush and steep serrated hills of the Powder River Breaks limit ideal breeding grounds and nesting locations. Extensive drilling during the coalbed methane boom, alongside several West Nile virus outbreaks, left the descendants of the surviving birds more reliant on the suitable habitat that remains.
Add in wildfire. In 2017, the Tidwell fire swept into Wyoming from Montana. Biologists would later say that it cut a protected zone of Greater Sage-grouse habitat, intended to provide connectivity between grouse populations in the two states, almost entirely in half.
The Northeast Wyoming Sage-Grouse Local Working Group, a coalition of biologists and local stakeholders, gathered to study options for a response. Wyoming is home to an estimated 37% of the world’s diminished sage-grouse population, but counts in the northeast trend significantly lower than those in the rest of the state. Once isolated, it becomes more difficult for regional populations to persist long term.
For decades, the working group has tended to sage-grouse health and habitat in the region, but as they studied the blackened landscape after the 2017 fire season, they discovered that the solution might require more than weed treatments and sagebrush plugs within a specific burn scar.
Since Wyoming’s sage-grouse core areas were last modified in 2015, shaped and regulated to guard habitat and forestall a looming endangered species listing, scientists had published a new body of research. The current maps leave areas now seen as critical to maintaining genetic connectivity with Montana are left entirely unprotected, the group wrote in a June management assessment summary.
Sage-grouse losses in the northeast would have impacts beyond the region. As energy development, more frequent fires, invasive annual grasses and the risk of weather extremes and ecosystem change due to global climate change increasingly threaten habitat and physically stress birds, the genes carried by the unique sage-grouse capable of living in rugged territory may contribute to the species’ overall health and survival.
SUB: Gathering feathers
Several years before tens of thousands of acres north of Sheridan burned in 2017, Brad Fedy, a professor at the University of Waterloo (Canada), began analyzing feathers. He and his colleagues sorted through thousands, all gathered, packed and mailed from sage-grouse breeding grounds (called leks) across the birds’ 11-state range.
Fedy spends his summers in the Powder River Basin and has a special affinity for sagebrush country and its famous strutting birds: delicate, fluffy and about the size of a chicken.
“Sage-grouse are an icon of the American West,” Fedy said. “If you’re in sage-grouse country, you’re in country I want to be in. Those landscapes – everything from the smells, the view, to the relentless sun to that overarching feeling that I didn’t evolve to be here. I’m not wanted here, and nature still has a lot of a lot of punch out there.”
The feathers informed a series of papers Fedy and his colleagues published between 2015 and 2018 that analyzed the connectivity patterns between sage-grouse populations in the West. Sage-grouse need good habitat, Fedy said, but robust species health also requires genetic diversity.
It’s like livestock, he said. “You can’t have related individuals breeding with each other and expect to have any sort of vigor in your population. And that’s the same with wildlife.”
Fedy made his first research trip to Sheridan in 2008, where he met with Tom Christiansen, then the sage-grouse coordinator for the Wyoming Game and Fish Department. The state’s sage-grouse experts knew then that connectivity was important, but they didn’t yet understand the specific genetic pathways.
Fedy told Christiansen that DNA could reveal some of those answers, kicking off a $4.5 million project that ultimately took eight years of development. Christiansen mailed baggies and a feather collection protocol to the agency employees and others conducting annual lek counts.
“Later on that summer, boxes of feathers started to arrive,” Fedy said. “Then, more boxes arrived and we had a 6-foot tall freezer jam-packed full of feathers.”
Working with partners from multiple federal agencies and universities, the researchers processed and analyzed data from almost 7,000 sage-grouse across the range, mapping which populations of birds had bred with one another over the past several generations.
The findings surprised them. When the computer model grouped genetically similar sage-grouse populations, it wasn’t the high peaks of the Rocky Mountains that marked the most significant divide across the range. Instead, a prominent barrier sliced diagonally across Wyoming, just below the northeast region.
The research, now published in several peer-reviewed journals, clearly showed: Powder River Basin birds are most closely connected to sage-grouse in Montana.
Northeast Wyoming is right on the edge of the bird’s geographic range, where the sagebrush communities of the Intermountain West melt toward the prairie. “That’s important because it means our birds are unique, they’re tougher birds, and they likely have unique local adaptations,” Fedy said at an Aug. 24 meeting.
“Range-edge individuals can be of greater conservation value than the core,” he added. “They’re more resilient. … If we have habitats change, it’s those individuals that can live on the edge, and the phenotypic expression of those genes that we’re going to need as stressors increase for the species.”
The state’s current core areas offer sage-grouse two north-south pillars of protection through Gillette and Buffalo. The Buffalo column links to some small but important leks in southern Montana, but Fedy’s research showed that the Gillette column provides the critical connection to the greater Montana population. Without some sort of an east-west path between the protected areas, the working group determined, isolation threatens local grouse.
SUB: The core strategy
Wyoming first adopted its sage-grouse core area strategy in 2008. After a steep population decline in the 1990s, the birds faced a potential Endangered Species Act listing. A team mapped out the highest-quality sage-grouse habitat for core designation, which limits development, noise and certain seasonal activities.
Yet northeast Wyoming presented a bit of a challenge. Coalbed methane was booming, and thousands of shallow wells were already scattered across the Powder River Basin. According to a 2012 report from the Bureau of Land Management Buffalo Field Office, between 2001 and 2005, the region’s sage-grouse population declined by 82%.
Unable to place additional restrictions on existing leases, the initial maps left “high, high quality habitat out of core,” according to BLM supervisory natural resources specialist Bill Ostheimer, a working group member.
As a result, the northeast core and connectivity areas today cover a lower percentage of the region’s critical leks than core areas in other parts of the state. Just 57.7% of the northeast’s peak male count was in core in 2020, compared with 82% in the rest of the state, according to Game and Fish statistics.
Expanding core to include 600,000 strategically selected acres across Sheridan, Campbell, and Johnson counties, the working group wrote, would increase the odds of maintaining connectivity by protecting the best-quality breeding habitat and would lift the percentage of peak males protected in the northeast to 77.6%.
That’s significant, because Game and Fish statistics show that leks located outside of the region’s core areas are disappearing at a faster rate than those that are protected, said the agency’s sage-grouse and sagebrush biologist, Leslie Schreiber.
The group drafted a proposal to alter core and connectivity areas in the region during the summer of 2019. That August, however, Gov. Mark Gordon released his updated Sage-grouse Executive Order, upending their process.
The order specified that in the event of a “soft trigger,” the population disturbance threshold met by the 2017 fire, a new stakeholder group called a “technical team” should be appointed by the Statewide Adaptive Management Working Group to analyze causal factors and make management recommendations. The northeast’s selected technical team has a similar makeup of industry and agency representation to the local working group, plus the addition of Fedy.
The working group nonetheless released a formal management summary this June to help inform state officials and the new technical team about the region’s top issues and the working group’s decision-making process.
“This is universal in ecology: The more you shrink a population, the more you isolate it, the greater risk it is of being extirpated,” said Fedy at the July meeting. “If we start losing things like sage-grouse, that’s a great indicator for the fact that you’re going to start losing a lot of things.”
SUB: Setting the course
As much as 65% to 95% of the genetic flow between sage-grouse populations in northeastern Wyoming takes place in the east-west corridor currently without formal habitat protections, according to the working group’s management summary.
Sage-grouse habitat dwindling. A 2005 U.S. Geological Survey report found that the average sagebrush patch size in the Powder River Basin had decreased by more than 63% over the preceding 40 years. “Once habitat is lost, research demonstrates that declines in sage-grouse numbers are permanent unless intensive and prohibitively expensive restoration is done,” Schreiber wrote in an email.
Wildfire is also an intensifying threat in the region, Schreiber said. Ostheimer described two “fire belts,” where lightning strikes frequently in prime sage-grouse habitat, one north of Sheridan and the other north of Gillette. Increasingly common invasive grasses dry early in the season, creating a mat of fine fuels that carries fire more readily than native plants.
“If we want to maintain sage-grouse in northeast Wyoming, we need to maintain that connectivity with Montana,” Fedy said at the August technical team meeting. “And the way you do that is by maintaining that habitat.”
The working group’s proposal would expand three core areas, shortening the distance between them and drawing in critical leks. It would also create a stepping-stone core area between the Buffalo Connectivity Area and the North Gillette Core Area, helping bridge the gap between those two populations.
Last summer, the working group began a public engagement process for the proposed changes, although the responsibility for making a recommendation transferred to the technical team before they could complete it. The working group made multiple public announcements, notified mining and oil and gas operators through the Wyoming Mining Association and the Petroleum Association of Wyoming, and sent 170 letters to local landowners whose property might be included in the proposed areas.
In response, they received “numerous” letters from landowners concerned that the expansion was not warranted and could affect their property rights or inhibit mineral development, according to the management assessment summary.
The current sage-grouse executive order doesn’t specifically constrain agriculture. “Properly managed grazing maintains or enhances Wyoming rangelands and helps sustain a diversity of plant species important to greater sage grouse habitat,” it reads. Strict restrictions on spacing and development of oil and gas drilling, however, could impact agricultural operations through the loss of potential revenues from surface use agreements or mineral royalty payments. The vast majority of the interest groups that attended a public meeting in Gillette represented extractive industries.
Members of the local working group attended each of the technical team’s meetings to answer questions and provide context about their own decision to recommend an expansion of core.
“The addition of key areas designated as core habitat would conserve additional nesting habitat, ultimately increasing the potential for genetic connectivity in northeast Wyoming and into Montana,” the group wrote in its summary. “The ultimate goal the (Northeast Working Group) hopes to achieve with the conservation of these areas is to improve the prospects of sage-grouse with the objective of preventing a future listing of the greater sage-grouse.” An Endangered Species Act listing, members pointed out during technical team meetings, could force greater land-use restrictions.
The technical team will next work to define the scope of its recommendations, members decided at their August meeting. The team’s mandate from the state is open-ended. It can to choose to focus on just the initial trigger – localized impacts from one fire, three years ago – or follow the working group’s path and search for landscape-scale solutions to keep sage-grouse returning each spring to the leks of the Powder River Basin.